Priniciples of Electromechanical Relay Operation
3.23 Contact Performance
The most widely used contact material in power relays are silver cadmium
oxide. This material requires rather high currents to weld and is, therefore,
well suited for heavy motor loads in which the inrush starting current may be
five to six times the steady state current. Contacts of power relays must also
be capable of opening at six to eight times the rated steady current in case a
motor should stall. These contact materials are well suited for power
application but should be avoided for low energy applications.